mfinegan@uceng.UC.EDU (michael k finegan) (09/01/90)
I had posted a 2D FFT in C, at request of someone in this group. The
version I posted had a small bug - a plus sign had been replaced by a minus.
For those who want the code, send E-mail to me; for those who want the fix :
- Mike
mfinegan@uceng.UC.EDU
about line #259 of posted C code ...>
replace this :
/* temp = complex multiply of w and array[isecnd][0] */
temp[0L] = w[0L]*array[eq_isecnd_row][eq_isecnd_col] -
w[1L]*array[eq_isecnd_row][eq_isecnd_col + 1L];
temp[1L] = w[1L]*array[eq_isecnd_row][eq_isecnd_col] -
w[0L]*array[eq_isecnd_row][eq_isecnd_col + 1L];
with this:
/* temp = complex multiply of w and array[isecnd][0] */
temp[0L] = w[0L]*array[eq_isecnd_row][eq_isecnd_col] -
w[1L]*array[eq_isecnd_row][eq_isecnd_col + 1L];
/* I have a few versions of this routine (I use it in a
* library); the net example (this one) had bogus complex
* multiply (- vs. +) - which Scott noticed :
* "I would appreciate if you would mention 'Scott Deifik'
* with the fix."
*/
temp[1L] = w[1L]*array[eq_isecnd_row][eq_isecnd_col] +
w[0L]*array[eq_isecnd_row][eq_isecnd_col + 1L];